Who knew software tweaking could have such a huge effect on battery life? Microsoft has just shown it's possible with an update for Windows 8.1 on the Surface Pro 2 which extends battery life by a huge 25 per cent.

Battery tests by Anandtech show the tablet can now last more than 8 hours while browsing the web over Wi-Fi. That's a jump up from 6.6 hours before the latest software update was released. It's also a 16 per cent video over Wi-Fi playback boost up to 7.75 hours from 6.65.

READ: Microsoft Surface Pro 2 review

Compared to the competition the Surface Pro 2 is still a bit behind, with it scoring 8.330 and the iPad Air scoring 9.480 and the Google Nexus 7 (2013) hitting 12.230. Microsoft told Anandtech that the tablet's various sensors, its higher resolution display, its active digitiser, and its capacitive touch screen all increase the amount of battery power required.